20643631104 has 104 divisors (see below), whose sum is σ = 56819590912. Its totient is φ = 6659112960.

The previous prime is 20643631061. The next prime is 20643631111. The reversal of 20643631104 is 40113634602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353832 + ... + 408024.

Almost surely, 2^20643631104 is an apocalyptic number.

20643631104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20643631104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28409795456).

20643631104 is an abundant number, since it is smaller than the sum of its proper divisors (36175959808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20643631104 is an equidigital number, since it uses as much as digits as its factorization.

20643631104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54251 (or 54229 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The spelling of 20643631104 in words is "twenty billion, six hundred forty-three million, six hundred thirty-one thousand, one hundred four".